Interoperability is of paramount importance in messaging. Senders of messages expect that messages will reach their destination and will be handled properly by the recipient's terminal, regardless of the type of terminal used by the recipient. However, emerging mobile terminals have made this requirement more challenging, due to the wide diversity of terminal characteristics such as display size and resolution, available memory, formats that are supported, etc. Furthermore, the network may also imposes limitations, such as a maximum size over User Data Protocol (UDP). A similar challenge exists in connection with information browsing, such that content is delivered and usable in an appropriate manner for the wide variety of current and future landline and mobile terminals.
Media content adaptation proxies could play an important role in maintaining interoperability and increasing user experience in many domains of applications such as messaging, browsing, etc. These proxies, commonly referred as transcoding proxies, transform media content to make it suitable for the destination terminal. For instance, one such transformation includes format conversion, e.g. Portable Network Graphics (PNG) to Graphics Interchange Format (GIF). In browsing situations, the origin server can also manage such adaptation to match the recipient's terminal capabilities.
However, in order to adapt the content to match the terminal characteristics, those characteristics must be known to the transcoding agent. Existing methodologies do not provide sufficient detail about the terminal characteristics or the user's preferences to adequately conform to the particular terminal. For example, the Session Initiation Protocol (SIP) Extensions for Instant Messaging and SIP Extensions for Presence does not provide any mechanism to discover the recipient's terminal capabilities to verify if the body of a SIP MESSAGE or NOTIFY method is supported by the recipient's terminal. A message is typically generated and sent without consideration of all the terminal capabilities. Nevertheless, the message originator usually expects that the message will reach its destination, and will be handled properly by the recipient's terminal.
This situation is not a significant problem for the short text messages that are mostly in use today. But the situation may become increasingly problematic as messages become composed of rich media components such as images, audio and video clips, etc. The proliferation of differing mobile terminals types and characteristics will also make this requirement more challenging. For instance, the received message may be too large for the recipient's terminal memory, or a mobile terminal may not support certain media types, or may support them only under certain conditions.
Thus, generalized terminal capabilities for the multitude of different terminal types simply does not provide enough information for today's content-rich communication. Rather than limiting the options to users of landline and mobile terminals, it would be desirable to provide a suitable manner of providing terminal characteristics and/or user preferences to a framework on which content can be responsively adapted. The present invention fulfills these and other needs, and offers other advantages over the prior art approaches.